The present invention relates to devices used to secure flexible material to concrete substrate such as cable to a wall, or tendon to bone. The present invention relates to a method, and a screw device therefor, for tensioning a cable such that rotation of the cable is prevented when the screw is turned.
Various fasteners have been described which provide compression to a surface. Standard screws provide an anchoring of the screw through the shear force exerted by the thread against the walls of the bore in which it is embedded. The head of the screw provides compression against the material. In situations where threads cannot purchase the material surrounding the bore, jackets surrounding the threads of the screw are often utilized. The jacket is designed to expand in the bore of the material and provide anchoring for the screw threads. Known screw devices cannot deliver a precise level of load to the cable or tendon tension. At present, when a cable is attached to a screw, or a sheath around the screw, and the screw is turned, the cable or sheath are not stabilized against rotation with respect to the substrate to which the screw is engaged
One type of known compressive bolt device consists of wings which provide compression to a surface of the material in which the device is mounted. Thus both sides of the bolt are compressing material as opposed to screws where one side is acting in shear. These devices generally are not wholly removable and require the wing side of the device to be left within or on the surface of the material within which the device was installed, when the bolt portion is removed.
Another type of known compressive bolt device includes winged bolts in which the device is wholly removable following use. Some of these devices are disclosed in U.S. Pat. No. 4,409,974 issued in 1983, which covers a bone-fixating surgical implant device.
The present device both provides a compression anchor and permits precise adjustment of the tension of an attached tendon or cable while preventing the tendon or cable from turning with appropriate instrumentation. The present device comprises an outer nut and an inner bolt to which a cable or tendon can be attached. By rotating the outer nut, the inner bolt is retracted in or out of the nut and hence tightening or loosening the cable or outer sheath.
The present invention provides a fixation device for bringing one object close to another by applying a compressive force on one or more surfaces of the objects being brought closer together. One end of the device is attached to a cable which is anchored in a second surface. One embodiment of the invention employs a sheath mounted around the shaft of a screw such that when the device is installed, the sheath is caused to expand radially outward as the screw is tightened.
Another embodiment of the device has a cylindrical inner shaft surrounded by a cylindrical sleeve, with a washer around the cylindrical sleeve. The inner shaft ends in an eyelet adapted to receive a cable or tendon. This device has slots in the end of the device, both on the inner shaft and on the outer nut, to receive a tool that can insert and deploy the bolt.
Yet another embodiment of this device employs a sheath surrounding a screw, an outer nut at one end of the screw, and a washer at the end of the screw, opposite the outer nut, such that by turning the outer nut the screw is brought closer to or further from the nut. In this way, the sheath of material is caused to expand radially outwardly from the screw. The sheath can be made of a single piece rigid material or a solid material. In the case of a solid material, there are longitudinal cuts in the sheath such that the longitudinal pieces can expand outwardly.
Still another embodiment of this device utilizes the Winged Compression Bolt disclosed in U.S. Pat. No. 5,098,433, which device comprises an outer sleeve surrounding a central screw and an outer nut threaded onto the outer sleeve. Turning the outer nut around the outer sleeve such that the wings of the device are pulled inward or outward from the nut, causing the outer sleeve, or sheath, to push radially outward on surrounding material. Holes in the wings will allow for a cable or tendon to be attached to the wings. When the other end of the cable or tendon is attached to second object, the cable or tendon can be loosened or tightened by turning the outer nut.
It has been discovered according to the present invention that because the nut can be rotated in increments, the cable or tendon can be adjusted in tension to a precise degree such that the cable attached to the end of the screw or the sheath put around the screw will be able to be put under tension or compression, respectively, to a precise degree.
It has also been discovered according to the present invention that by using a cylindrical sheath, which is split longitudinally, along with a washer having a ridge on it, the sheath can be caused to push radially outward in a uniform fashion when the nut is tightened about the screw.
It has also been discovered according to the present invention that if the sheath around the sleeve is made of a soft material, the sheath can be of a single piece and made to expand uniformly outward from the threaded shaft when the nut is tightened about the screw.
It has also been discovered according to this invention that the tools which deploy the nut and screw can stabilize the inner screw and rotate the outer nut.
It is therefore an object of this invention to provide an apparatus having a sheath which creates a compressive force on an area of surrounding material with a sheath around its shaft or as a result of creating a tensile force on a tendon or cable attached to an end of the shaft such that the device will maintain the surrounding material in a steady, non-rotating manner while compressing or loosening the material.
It is further an object of this invention to provide a fixation device that is removable from the hole when it is desired to be removed.
Accordingly, the present invention provides a tension adjusting device for creating tension on material comprising:
a. a hollow outer nut (sleeve) having a sidewall enclosing a centrally disposed opening within the nut, a front end and a rear end;
b. an elongated shaft having a first end and a second end, which shaft is movable and within the opening in the hollow outer nut;
wherein the mean length of the device is adjusted by changing the relationship outer nut and elongated shaft.
Some preferred embodiments of the invention include those wherein: 1) the hollow outer nut is rotatable around the elongated shaft; 2) the shaft is threaded and has a slot at one end; 3) the nut comprises an internally threaded cylinder; 3) the elongated shaft is threaded and has a flat surface on it by which it can be engaged to stabilize it while the nut is rotated about it; 4) the elongated shaft has hole or securing coupling at an end to allow it to attach a material which requires anchoring; 5) the outer nut is rotatable while the inner elongated shaft is stabilized thereby causing the inner shaft to move within the sleeve such that any material attached to the shaft can be tightened; 6) the device comprises an inner sleeve and the outer nut is movable against the inner sleeve such that the sleeve is more or less contained within the outer nut; 7) the elongated shaft is threaded and has a slot at the first end and further comprises a washer or xe2x80x9cOxe2x80x9d ring at the opposite second end, wherein the washer or xe2x80x9cOxe2x80x9d ring is rotatably engaged with the shaft so as to provide compression on a material; 8) the device further comprises a first grooved nut below an xe2x80x9cOxe2x80x9d ring at the first end of the shaft and a second grooved nut is placed on a surface of the nut such that the grooves are facing each other; 9) a cylinder of material is placed between the ends of the device; 10) a split cylinder of material is placed between two xe2x80x9cOxe2x80x9d rings onto which grooved washers have been placed such that the cylinder can split and expand radially outward along the length of the cylinder; 11) the elongated shaft is a winged compression bolt; 12) the elongated shaft is a winged compression bolt, a cylinder of material is placed around a sleeve of the compression bolt, and a grooved washer is placed near the outer nut; and 13) the elongated shaft is a winged compression bolt, a cylinder of material is placed around the compression bolt, and a grooved washer is placed near the outer nut, wherein the cylinder is caused to expand radially outward when the outer nut is rotated and the compression bolt is held stable.
Another aspect of the invention provides a method of tensioning a cable or tendon by drilling a bore in a matrix and attaching the tendon or cable to a second matrix at a far point in the bore and the other side of the cable or tendon to the end of a threaded shaft. A nut is placed around the threaded shaft and a movable washer is placed around the nut such that it makes contact with the surface of the matrix into which the bore has been drilled. By turning the nut which is rotatably attached to the washer, the cable or tendon is tightened in a manner such that the cable or tendon is maintained in a stable, non-rotating fashion during this process, putting tension on the cable or tendon.
Still another aspect of the invention provides a method for plugging a hole in a single material or a hole straddling two separate materials by drilling a bore in the material or obliquely or lengthwise to the interface of the two materials such that the bore straddles the two materials. A threaded shaft with a nut and washer at one end and a washer at the other end and a matrix sheath surrounding the threaded shaft is placed in the bore and the nut is turned, compressing the matrix radially outward into the walls of the bore in the substance, creating a compressive contact along the length of the bore between the walls of the bore and the inserted matrix.
Yet another aspect of the invention provides a method for plugging a single material or a hole straddling two separate materials by drilling a bore in the material or obliquely or lengthwise drilling a bore such that it straddles the two materials. A rigid matrix with longitudinal splits is put around a threaded shaft. At one end there is a nut with a washer arrangement and at the other end there is a washer or perpendicularly deployed wings. At the nut end or at both the nut end and the opposite end, a washer with a ridge is placed such that the ridge interfaces with the split in the matrix jacket. The threaded shaft, and matrix material is put into the bore in the bone and the washer is set around the nut on the surface of the bore. The nut is turned, causing the matrix to separate along the splits and move radially outward toward the walls of the bore.
Still yet another aspect of the invention provides a method for both plugging a bore within a single matrix or across two matrices while putting tension on a cable or tendon such that a hole is bored into the single matrix or along the interface of the two matrices or obliquely to the two matrices. A cable or tendon is attached to another surface at a distant part of the bore or deep within the bore and its second end is attached to a threaded shaft with a hole in its end or in its perpendicular wing. Around the threaded shaft is a third matrix which is either a single cylinder or a cylinder which has been cut longitudinally. At one end of the threaded shaft, below the holes is a movable washer. At the other end is a nut which is set in a moveable washer. The threaded shaft and the third matrix is placed in the bore with the washer against the surface of the third matrix around the bore and the nut is turned. This causes retraction of the cable or tendon creating tension on it while at the same time, causing the third matrix around the threaded shaft to be forced radially outward into the surrounding bore which is in the single matrix or two matrices.
In one embodiment, the invention provides a device for adjusting the tension on a cable by applying a compression force to an anchor surface of a matrix, said device including:
a compression member having a body and a threaded bore therethrough, said body having at least one compression surface for applying said compression fixation force to said anchor surface of said matrix; and
a shaft having a threaded portion at one end for mating with said threaded bore and further having a receptacle at the other end thereof for receiving said cable to be tensioned; said compression member being adapted to be rotated around said shaft while said shaft is adapted to be stabilized against rotation to prevent torsion of said cable, wherein said cable is a tendon or ligament.
In another embodiment, the invention provides a device for adjusting the tension on a cable by applying a compression force to an anchor surface of a matrix, said device including:
a compression member having a body and a threaded bore therethrough, said body having at least one compression surface for applying said compression fixation force to said anchor surface of said matrix; and
a shaft having a threaded portion at one end for mating with said threaded bore and further having a receptacle at the other end thereof for receiving said cable to be tensioned; said compression member being adapted to be rotated around said shaft is adapted to be stabilized against rotation to prevent torsion of said cable, wherein said matrix is bone.
In still another embodiment, the invention provides a method for adjusting the tension on a cable including the following steps:
applying a compressive fixation force to an anchor surface of a matrix, using a compression member having a body and threaded bore therethrough and at least one compression surface for applying said compression fixation force to said anchor surface and a shaft having a threaded portion at one end thereof for mating with said threaded bore and further having a receptacle at the other end thereof for receiving the cable:
attaching the cable to said receptacle;
stabilizing the shaft against rotation to prevent torsion of said cable; and
rotating the compression member around said shaft, wherein said cable is a tendon.
Yet another embodiment of the invention provides a method for adjusting the tension on a cable including the following steps:
applying a compressive fixation force to an anchor surface of a matrix, using a compression member having a body and threaded bore therethrough and at least one compression surface for applying said compression fixation force to said anchor surface and a shaft having a threaded portion at one end thereof for mating with said threaded bore and further having a receptacle at the other end thereof for receiving the cable:
attaching the cable to said receptacle;
stabilizing the shaft against rotation to prevent torsion of said cable; and
rotating the compression member around said shaft, wherein said matrix is bone.